#pragma GCC optimize(2, "Ofast", "inline")
#include <iostream>
#include <vector>
#include <map>
#include <cmath>
#include <set>
#include <queue>
#include <stack>
#include <list>
#include <unordered_map>
#include <algorithm>
#define endl '\n'
#define int long long
#define pii pair<int, int>
using namespace std;

// 已知
int n, l, r;
string s;
// 未知

signed main()
{
    cin.tie(0)->sync_with_stdio(0);
    cout.tie(0);
    cin >> n >> l >> r>>s;
    r--,l--;
    for(int i=l;i<=r;++i)
    {
        if(s[i]!='o')
        {
            cout<<"No"<<endl;
            return 0;
        }
    }
    cout<<"Yes"<<endl;
    return 0;
}